Conduit bender



Aug. 20, 1946.

.J. H. ABRIAMYsoN ETAL CONDUIT ABENDER 'Filed Apri; 2e, 1943 2Sheets-Sheet l Patented Aug. 2Q, 1946 CONDUIT BENDER John HerbertAbramson and Edwin C. Swanson, Rockford, Ill., assignors to GreenleeBros. & Co., Rockford, Ill., a corporation of Illinois Application April26, 1943, Serial No. 484560 12 claims.

This invention relates to a new and improved portable hydraulicbendingdevice especially Adesigned and adapted for operating on conduitused in electrical wiring, but suitable for bending various kinds ofthin walled metal tubes and pipes Without danger of objectionabledistortion or flattening thereof.

In our VPatent 1,964,550, we disclosed a hydraulic bender in which thepipe or conduit to be bent was supported in the device at spaced points,and a shoe arranged to bear against the pipe so conduit between thesepoints was given lineal movement to bend the pipe or conduit. It istheprincipal object of our present invention to provide a hydraulic benderof the same general type but having a larger substantially semi-circularshoe movable lineally, the peripheral groove in Awhich is conformed to tthe inner side of the bend ultimately made in the conduit a pair ofrollers being provided, guided for arcuate movement away from oneanother with respect to the periphery of the lineally movable arcuateshoe and operatively interconnected with the shoe andthestationary bodyor frame, so as to be vgiven movement in timed relation .with theshoeauxiliary shoes to be interposed between the arcuate shoe and therollers and provided with grooves of corresponding width, whereby anylikelihoodof serious distortion or ilattening of the pipe or conduit inthe bending thereof is avoided.

, -Theurollers, in accordance with our invention, are of an ordinarycylindrical form and are H'adapted to roll on'the flat backs of theauxiliary slices, and in that way one set of rollers will serve for allpurposes, a dierent arcuate shoe and different auxiliary shoes being'provided for 'different' outside diameters of pipe or conduit.

The linkage interconnecting the rollers with lthe arcuate shoe andstationary body or frame .may-', in accordance withV our invention, beadjusted for different radii of bends, `and in the vpreferred form ofour device, we vprovide a pair o f extension or adapter platesinterposedbetween `the stationary body or framel and the innery ends ofthe rolleractuating links otherwise pivotally connected directly to the body orframe, whereby to permit pivotally connecting said links to the body atpoints spaced outwardly from the end of the body on opposite sides ofthe pivot point for therroller, guiding links, because we have foundthat this makes for the easiest and smoothest operation throughout therange of bending. Y lTheV invention is illustrated in the accompanyingdrawings, in which- Y Figs. v1 and 2 are face views of the bender of ourinvention with only a portion of the stationary body or frame shown, thedevice in Fig. 1 being illustrated at thebeginning of a bending.operation and in Fig. 2 at the end of a 180 bending operation; f f

Fig. 3 is a sectional view taken mainly on the line 3 3 of Fig. 1, withcertain portions shown in side elevation to better illustrate theconstruction, and

Figs. 4, 5, and 6 illustrate other devices similar to that. of Figs. 1to 3 but-embodying dilerent linkages.

. Similar reference numerals are applied to corresponding partsthroughout the views,

. Referring first to Figs. 1 to 3, the reference Vnumeral lli designatesthe stationary body or `frameof the device, in which is preferablyprovideda cylinder bore H for the piston l2. In our Patent 1,964,550,mentioned above, we disclose the complete, manually operable, hydraulicApump mechanism for injecting oil or other fluid under high pressureinto the cylinder H behind the piston l2 by. oscillatory movement of ahand lever, special provision being made to limit the outward lmovement,of the piston at a predetermined point to prevent accidentaldisplacement A of the piston from the cylinder, as, f or example, when.the piston l2 reaches the` extreme position shown in Fig. 2. In thepatent there is also a .disclosure of means operable to permit liuid toflow out of the cylinder so that the piston may beqretracted and, ofcourse, a similar provision is .necessary in the present device, if thesame is hydraulically operated.

to whatever specic operating means may be employed for forcibly movingthe ram with respect to the body or frame.

In accordance with the present invention, an arcuate shoe I3 is mountedon a crosshead I4 suitably attached to the outer end of the piston I2,as by engagement of a dowel pin projection I on the end of the piston ina socket I6 provided therefor in the crosshead, and this arcuate shoecooperates with a pair of auxiliary straight shoes I'I and I8 andmovable rollers I9 and 20 that are interconnected with the shoe I3 andbody I0 so that arcuate movement is given the rollers in the linealmovement of the shoe to, bend the conduit 2I interposed between thearcuate shoe I3 and the auxiliary shoes II and I8. The body I0 has apair of pivot pins 22 and 23 mounted thereon in spaced parallelrelationship on opposite sides of the piston I2, and although, ashereinafter disclosed, certain of the links connected to the rollers maybepivoted to the body directly on these pins, we have shown in Figs. 1,2, and 3 extension or adapter plates 24 mounted on the body byengagement of the pins 22 and 23 in holes 25 in the plates. The adapterplates have rauxiliary pivot pins 22a and 23a provided thereon Yinoutwardly spaced parallel relation to the pins 22 and 23, respectively,and on opposite sides of the piston I2, as shown, for pivotal connectionof tension links 2liv and 21 with the body I0 through the medium of theadapter plates 24. Pivot pins 28 and 29 extend through holes 30 in theouter ends of the links 26 and 2I--for rotary Vsupport of the rollers I9and 20. Other holes 3| and 32 are provided in these links in inwardlylongitudinally spaced relation to the holes to permit' setting therollers I9 and 2|] farther inwardly,` as, for example, where bends onshorter radiiare to be made. In a similar manner, links yor arms 33 and34, which are shown pivotally connected with the pins 28 and 29 byengagement of the pins in holes 35 in the cuter ends of the links, haveother holes 36 and 31 provided therein ofthe pivot pins or trunnions, itwill, of course,v be understood that they may be provided, and usuallyare.

A half-round groove 39 is provided in the periphery of the shoe I3, andcorresponding'halfround grooves 40 are provided in the inner sides ofthe auxiliary shoes I1 and I 8. These grooves 39 and 40 are ofapproximately the same diamelter as the outside diameter of the pipe orconduit to be bent, but are preferably slightly narrower than the pipeor conduit, so as to have tight engagement on the diametrically oppositesides of the pipe or conduit, asV indicated at 4I in Fig. 3,

and ample working clearance at allpoints therebetween, as indicated at42 inthe same figure.

' In that way the pipe or conduit being bent is conned on the sides bythe cooperating shoes I3, `I`I, and I8 as between dies and there is nodanger of any excessive distortion or nattening. This `isparticularlyimportant in thinner walledtubes, and it must be remembered that for theduration all conduit available generally is unusually thin walle'd. A nY i The rollers I9 and 20 are of cylindrical form and are adaptedto runon flat track surfaces 43 provided on the backs of the auxiliary shoesThe links 33 and 34 are pivotally Y I'I and I8. In that way the samerollers serve for all purposes, different shoes being used for differentdiameters of pipe or conduit to be bent. Diierences in the radius ofbending are accommodated by the provision of the longitudinally spacedholes 39, 3I, and 32 in the links 26 and 21 and cooperatinglongitudinally spaced holes 35, 36, and 3l in the links 33 and 34. Thesetup illustrated in Figs. 1, 2, and 3 is for the largest radiusbending.

In operation, the pipe or conduit to be bent is placed between thearcuate shoe I3 and the auxiliary straight shoes I'I and I8, asindicated at 2I in Fig. l, and then lineal movement is given the shoe I3and at the same time the rollers I9 and 20 are given arcuate movement inopposite directions in timed relation with the shoe I3, by reason oftheir interconnection with the shoe I3 and the stationary body Vor frameI0. The rollers maintain the same space relationship to the periphery ofthe arcuate shoe I3 throughout their movement thereby causing theauxiliary shoes Il and I8 to bend the pipe or conduit to the samecurvature as the shoe I3. The operator may, of course, stop the bendingoperation at any intermediate point and check the included angle, so asnot to bend the pipe or conduit too far. Any bend up to and even beyond,is possible with the present device,.and it should be apparent that thebend for any angle will be on a unlform radius, due to the fact that theshoe I3 selected for a specic bend fits the inner curvature of theultimate bend and the rollers I9 and 20 in each set-up are set to beguided to follow the curvature of the arcuate shoe selected. A number ofshoes I3 of different radii and having different width grooves 39 willbe provided with each 'bender to accommodate a given range of operation,and a number of pairs of auxiliary shoes Il and I8'having differentwidth grooves will also be provided.

The bender shown in Fig. 4 is similar to that of Figs. l to' 3, but haslinks 26 and 21 directly connected to the stationary body or frame I0 bymeans of. the pivot pins 22 and 23, the adapter plates 24 being omitted.The device of Fig. 4 is otherwise like that of Figs. 1, 2, and 3, andthe operation is substantially the same.

In Fig. 5 a device is shown in which the links 26 and 21" are the onlyones used for causing the rollers I9 and 20 to operate the auxiliaryshoes I'I' and I8 in the lineal movement of the arcuate shoe I3 so as tobend the pipe or conduit 2l to the curvature of the shoe. Such a set-upmay be made more quickly than that of Fig. 4 and will be satisfactoryunder certain conditions, as, for example, Where only small angle bendsare to be made, and in other cases where it is not as important toinsure accurate guiding of the rollers I9 and 2B around the arc 0f theshoe i3 and in accurately timed relation with the movement of the shoe.Otherwise the operation is similar to that of Figs. l to 3 and Fig. 4.

The device shown in Fig. 6 is the same as that of Figs. 1 to Band Fig. 4ih so far as the sta.- tionary body or' frame I and the relativelymovable arcuate shoe I3 are concerned, and also in -so far as therollers I9 and 20 cooperating with device. The links 26a. and 21a fortransmitting arcuate Ymovement to the rollers I9 and 20 are shelter thanthe links 2s and 21 and are pivotally connected at one end to thestationary body or frame l0 .and at `the other end to the links 33a and.34a, at Apoints intermediate the ends thereof, as indicated at 55. Thelinks 33a and 34a are otherwise like the links 33 and 34 of Figs. l. to3 and Fig. 4, being provided with v.longitudinally spaced holes 35, 36,and 31 in the outer end portions thereof for reception of the pins 28and 29 in any one of three different positions of adjustment, dependingupon the radius of the bend to be made and accordinglyvthe radius of theshoe I3 selected. The operation of this bender is substantially the sameas that of Figs. 1 to 3 or that of Fig/l.

AIt is believed the foregoing description conveys a good understandingof the objects and advantagesof our invention. The appended claims havebeen drawn to cover all legitimate modifications and adaptations.

We claim:

1. In a bending device, the combination of a pair of elements comprisinga frame member and a driven member relatively movable lineally havingsuitable means for so moving the same, an arcuate shoe wholly carried onand movable lineally `with the driven member relative to the framememberl to bring the shoe into engagement with anobject to be bent at apoint intermediate the ends of the arc thereof to conform theobjectwmore or less to the lcurvature of said shoe, a pair ofcooperating bending elements adapted to initial- 1y engage the oppositeside of the object to be bent at spaced points on opposite sides of thepointv of initial engagement of the shoe with said object, means forguiding said bending elements to move in opposite directions from saidspaced points in arcs substantially followingthe curvature of said shoe,and means for pivotally connecting said bending elements withthe framemember to support the bending elements thereon whereby to cause arcuatemovement of said bending elements, in response to the lineal movement ofthe shoe. y

2. In a bending device. the combination of a pair of elements relativelymovable lineally hav- -ing suitable means for so moving the same, anarcuate shoe movable lineally with one of said elements relative to theother and arranged to engage an object to be bent at a pointVintermediate the ends of the arc thereof to conform the object more orless to the curvature of said shoe, a pair of cooperating bendingelements adapted to engage the opposite side of the object to be bent atspaced'points on opposite sides of the point of initial engagement ofthe shoe withsaid object, arms pivoted on an axis movable with said shoefor oscillatory movement relative to the shoe on an axis substantiallycoincident with the center of the arc of said shoe and supporting saidbending elements for arcuate movement substantially following thecurvature of said shoe, and tension members interconnecting said armswith' the other of said relatively movable elements whereby said armsare given oscillatory movement in response to the lineal movement ofsaid shoe.

3. A bending device as set forth in claim 2, wherein the bendingelements are adjustable to diiferent positions on the outer ends of saidarms to change the radius of operation thereof.

4. A bending device as set forth in claim2, wherein the bending elementsare adjustable to different positions on the outer ends of said arms toch'ange the radius of operation thereof, and wherein the arcuate shoe isremovable from the iirst of said relatively movable elements to permitsubstitution of another ,arcuate shoe of different radius. y f

5. In a bending device, thecombination of a pair of elements relativelymovable lineally having suitable means for so moving the same, anarcuate shoe movable lineally with one of said elements relative to theother and arranged to engage an object to be bentat a point intermediatethe ends of th'e arc thereof to conform the object more or less Ito thecurvature of said shoe, a pair of auxiliary shoes to engage the oppositeside of the object, a pair of bending elements cooperating with saidauxiliary shoes at spaced points on opposite sides ofthe point ofinitial engagemenil-I of the arcuate shoe with said object, arms pivotedfor oscillatory movement relative to the arcuate shoe on an axissubstantially coincident with' the center of the arc of said shoe forsupporting said bending elements and for arcuate movement thereofsubstantially followingY the curvature of said shoe, and tension linkspivotally connected at one end to the other of said relaftively movableelements for rotation. on a xed axis and at the other end to the armsto' cause substantially equal oscillatory movement of the latter inresponse to the lineal movement of the arcuate shoe in compressing saidobject.

6. A bending'device as set forth in'claimV 5, wh'erein the bendingelements are adjustablejon .said arms to different positions inlongitudinally spaced relation relative to the outer endsof said arms tochange the radius of operation thereof, said device including anextension member adapted to be interposed between the links and the saidother of the relatively movable elements for pivotal connection of saidlinks on said element but at points closer to the' arcuate shoe.

'7. In a portable conduit or pipe bending device, the combination of aframe'andY a driven member movable lineally on the frame having suitablemeans for' so moving the same, an arcuate shoe on said driven membermovable lineally therewith arranged to engagea conduit to be bentl at apoint intermediate the ends'of the arc of the shoe, said shoe having aperipheral groove to receive the conduit, `a pair of substantiallystraightv auxiliary shoes having grooves provided therein to engage theconduit from thev opposite side relative to the arcuate shoe, a pair ofrollers adapted to engage the outer sides of the auxiliary shoes atspaced points on opposite sides of the point of initial engagement ofthe arcuate shoe with' said conduit to bend the conduit more or lessto'v the curvature of the arcuate shoe, arms pivotally connected withsaid arcuate shoe for oscillatory movement relativev thereto on an axissubstantially coincident with the center of the arc of said arcuate shoeforsupporting said rollers for substantially equal arcuate movement awayfrom said spaced points substantially following the curvature of saidshoe, and tension links interconnecting said arms with frame to impartoscillatory movement to said rollers in response to the lineal movementof said shoe.

8. A conduit bending device as set forth in claim '7, wherein thefollowers are adjustable to different positions in longitudinally spacedrelation relative to the outer ends of said arms to change the radius ofoperation thereof.

9. In a portable conduit or pipe bending device, the combination of aframe and a driven member movable lineally on the frame having suitablemeans for so moving the same, an arcuate shoe on said driven membermovable lineally therewith arranged to engage a conduit to be 7 bent ata point intermediate the ends ofthe arc thereoLysaid shoe having aperipheral groove to receive the conduit, a pair of substantiallystraight auxiliary shoes having grooves provided therein toengage theconduit from the opposite side relative to the arcuate shoe, a pair ofcylindrical .rollers adapted to engage at surfaces on the outer sides ofthe auxiliary shoes at spaced points y on 'opposite sides of the pointof initial engagement of the arcuate shoe with said object to bendthe'object more or less to the curvature of the arcuate shoe, armsdisposed on opposite sides of said shoes having ends pivoted formovement with saidl arcuate shoe and for oscillatory movement 'relative'to the shoe on an axis substantially coincident with the center of thearc of said shoe, the opposite ends of said arms rotatably supportingopposite ends of said rollers for arcuate movement substantiallyfollowing the curvature of said shoe, and tension links on oppositesides of said shoes pivotally connected at one end to the frame vfor`rotation on a fixed axis and at the other end to said arms to causeoscillatory movement of the latter in the lineal movementl of the shoein compressing the conduit.'

10. In a conduit or'pipe bending device, the combination of a pair ofelements relatively movable lineally having suitablemeans for so'movingthe same, an arcuate shoe movable lineally with one of said elementsrelative to the other and arranged to engage a conduit to be bent at apoint intermediate the ends 'of the are thereof, said shoe having aperipheral groove to receive the conduit, a pair of substantiallystraight auxiliary shoes having grooves provided therein to engage theconduit from the opposite side relative to the arcuate shoe, a pair ofcylindrical rollers adapted to engage flat surfaces on the outer sidesof the auxiliary shoes at spaced points Von opposite sides of the pointof initial engagement of the arcuate shoe with said conduit to bend theconduit more or less to the curvature of the arcuate shoe, a pair ofarms disposed on opposite sides of said arcuate shoe, the arms of Veachpair having one end pivotally connected together and the opposite endspivotally connected Vto said rollers to support opposite ends thereoffor arcuate movement substantially following the curvature of said shoe,said arms acting to cause the rollers to move away from said spacedpoints at the same rate, and links pivotally connected at one end to theother of said relatively movable elements for rotation on a fixed axisand at the other end to said rollers to impart arcuate movement to saidrollers in response to lineal movement of the arcuate shoe.

vicel-'ofa frame member and `a driven .member movable with respectthereto, an arcuate bending shoe' supported on said driven membermovable lineally therewith into engagement with a tube to be bentintermediate the ends of the latter, a pair of substantially straightauxiliarybending shoes to engage the tube from the opposite'siderelative to said arcuate shoe, a pair of'followers adapted to engage theouter sides of the auxiliary shoesY at Vspaced points on oppositesidesof the point of initial engagement of the arcuate shoe with thetube, a plurality of substantially straight links pivotally supported onone end on said frame member for supporting said followers on the framemember at said spaced points and produce a lateral component of force tomove the followers away from each other and peripherally of the arcuateshoe in response to movement of said driven member with respect to theframe member in a direction to force the arcuate shoe against the tubein a bending stroke, and arms connected at one end to said followers andpivotally interconnected at their opposite ends to cause said followersto move away from said spaced points at substantially the same rate.

12. The combination in a tube bending device of a frame membercomprising a liuid cylinder and a driven member comprising apistondisposed therein and movable lineally with respect thereto, anarcuatebending shoe on said piston projecting beyond the end thereof andmovable lineally therewith into engagement with a tube to be bent at apoint intermediate the ends of the arc of the shoe, a pair of loosesubstantially straight auxiliary bending shoes to engage the tube fromthe opposite side relative to 'said arcuate shoe, a pair of followersadapted to engage the outer sides of the auxiliary shoes at spacedpoints on opposite sides of the point of initial engagement of thearcuate shoe with the tube, a plurality of substantially straighttension links disposed on opposite sides of said shoes to support thesame therebetween, said links being pivotally supported at one end onsaid frame member for pivotally supporting said followers on said framemember at said spaced points and thereby produce a lateral component offorce to move the followers arcuately substantially following thecurvature of the arcuate shoe in response to movement of said arcuateshoe against the tube in a bending stroke, and means interconnectingsaid followers for equalizing the lateral force applied thereto to causethe followers to move away frcm said spaced points at substantially thesame ra e.

JOHN HERBERT ABRAMSON. EDWIN C. SWANSON.

